1. Field of the Invention
This invention is related to an improvement in the structure of a windshield wiper blade assembly and in particular to one which can provide a high downward pressure to the rubber blade against the windshield upon the bearing of the force of the wind.
2. Description of the Prior Art
Referring to FIG. 1, the conventional windshield wiper blade assembly includes an arched casing 11 for connection to a wiper drive arm 15, a rubber blade 14, two assistant blade holders 13 fastened to the top of the rubber blade 14, and two master blade holders 12 pivoted to two opposite ends of the arched casing 11 and connected between two opposite ends of the rubber blade 14 and the hvo assistant blade holders 13. When in use, the side wall of the arched casing 11 bears the force of the wind, and so when the force of the wind increases, the arched casing 11 tends to be forced to vibrate the rubber blade 14. However, as the rubber blade 14 is vibrated, it cannot remove rain water from the windshield effectively. Hence, it has been proposed to form a spoiler 17 extending outwardly from one side of the arched casing 11 so as to increase the thrust on the windshield wiper. However, the downward pressure on the assistant blade holders is insufficient to keep from vibration because of the following reason:
Suppose the pressure exerted on the arched casing 11 be equal to 100 units (i.e. 50 units of the pressure exerted by the wiper drive arm 15 plus 50 units of the pressure exerted by the spoiler 17), and 20% of the pressure be reduced for each connection. Then, the pressure transmitted from the arched casing 11 to the master blade holder 12 will be reduced by 20% of the pressure exerted on the arched casing 11. That is, 100 unitsxc3x97(100xe2x88x9220)/100=80 units. Similarly, the pressure transmitted from the master blade holder 12 to the assistant blade holder 13 will be reduced by 20% of the pressure exerted on the master blade holder 12. That is, 80 unitsxc3x97(100xe2x88x9220)/100=64 units. Accordingly, the pressure exerted on the assistant blade holder 13 will be only 64% of the pressure exerted on the arched casing 11, thereby malting it insatisfactory in use.
Therefore, it is an object of the present invention to provide an improvement in the structure of a windshield wiper blade assembly which can obviate and mitigate the above-mentioned drawbacks.
This invention is related to an improvement in the structure of a windshield wiper blade assembly.
According to a preferred embodiment of the present invention, a windshield wiper blade assembly includes an arched casing having an intermediate portion provided with a seat provided a rod, the arched casing having two arms each provided with a pair of opposite first pins, a pair of master blade holders each having a spoiler with two gradually decreasing ends each formed with a recess and provided with two aligned holes, the spoiler having two turbulent holes and a through hole between the two turbulent holes, the arched casing being engaged with the master blade holders with the pins engaged with the aligned holes, the master blade holders having a bottom formed with two longitudinal grooves, a pair of assistant blade holders each having an intermediate portion provided with a protruded end configured to engage with the recess of the spoiler, two second pins arranged under the protruded end adapted to engage with the aligned holes of the master blade holder, and a bottom provided with two protuberances each having a longitudinal groove, and a rubber blade fitted in the longitudinal grooves of the master and assistant blade holders.
It is the primary object of the present invention to provide an improvement in the structure of a windshield wiper blade assembly which can provide a high downward pressure to the rubber blade against the windshield upon the bearing of the force of the wind.
It is another object of the present invention to provide an improvement in the structure of a windshield wiper blade assembly which is durable in use.
The foregoing objects and summary provide only a brief introduction to the present invention. To fully appreciate these and other objects of the present invention as well as the invention itself, all of which will become apparent to those skilled in the art, the following detailed description of the invention and the claims should be read in conjunction with the accompanying drawings. Throughout the specification and drawings identical reference numerals refer to identical or similar parts. Many other advantages and features of the present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying sheets of drawings in which a preferred structural embodiment incorporating the principles of the present invention is shown by way of illustrative example.